Abstract
The pituitary functions were tested in two males with the typical clinical pictures of hypogonadism. The secretions of ACTH, TSH, GH and prolactin in these patients were maintained within normal limits, whereas they had markedly diminished LH and FSH levels in plasma. Plasma LH and FSH responses to the intravenous injection of 100μg LH-RH were absent or limited. After 7-day treatment with intravenous infusion of 400μg LH-RH, they showed normal or improved responses to the intravenous injection of 100μg LH-RH. Thus, the diagnosis of isolated gonadotropin deficiency due to a hypothalamic lesion was established. Initially, the standard LH-RH test (100μg intravenous injection) did not elicit a rise in plasma GH levels. However, it was of interest that after the repeated stimulation by 400μg LH-RH, GH response to the intravenous injection of 100μg LH-RH was observed in both patients.
